Chapter 5: Extensions: Write Your Own Octave Functions

Understanding functions

1	a) Missing function keyword	b) Missing commas in the argument list
	e) The second output is undefined	f) The output variable not defined.
	Note that in d) the help text is misplaced
2	Number of input arguments, (Number of ARGuments IN)
	Number of output arguments (Number of ARGuments OUT)

Implementing mathematical functions as Octave functions

a) function f = fun(x) f = x + sin(x); endfunction	b) function f = fun(t) f = [sin(t), t.^2, cos(t)]; endfunction
c) function f = fun(x) f = x + y./z; endfunction	d) function f = fun(t) global global_o; f =exp(-I.*global_o.* t); endfunction
Notice that the functions are vectorized

Understanding vectorization

a) b = A(:,1) + 1.0;	b) i=find(a>1.0); s=sum(a(i));
c) n=length(a); b = a(1:2:n);	d) n=length(a); c = 0.5.*(a(2:n) a(1:n-1));